The present invention relates to nonwoven material and, more particularly, to nonwoven fibrous hydraulically entangled web material, wherein the nonwoven hydraulically entangled material is a hydraulically entangled non-elastic web of at least one layer of meltblown fibers and at least one layer of nonwoven, e.g., fibrous, material such as pulp fibers, staple fibers, meltblown fibers, continuous filaments, nets, foams, etc. Such material has applications for wipes, tissues, bibs, napkins, cover-stock or protective clothing substrates, diapers, feminine napkins, laminates and medical fabrics, among other uses.
Moreover, the present invention relates to methods of forming such nonwoven non-elastic material by hydraulic entangling techniques.
It has been desired to provide a nonwoven material having improved hand and drape without sacrificing strength and integrity.
U.S. Pat. No. 3,485,706 to Evans, the contents of which are incorporated herein by reference, discloses a textile-like nonwoven fabric and a process and apparatus for its production, wherein the fabric has fibers randomly entangled with each other in a repeating pattern of localized entangled regions interconnected by fibers extending between adjacent entangled regions. The process disclosed in this patent involves supporting a layer of fibrous material on an apertured patterning member for treatment, jetting liquid supplied at pressures of at least 200 pounds per square inch (psi) gage to form streams having over 23,000 energy flux in foot-poundals/inch.sup.2.seconds at the treatment distance, and traversing the supporting layer of fibrous material with the streams to entangle fibers in a pattern determined by the supporting member, using a sufficient amount of treatment to produce uniformly patterned fabric. The initial material is disclosed to consist of any web, mat, batt or the like of loose fibers disposed in random relationship with one another or in any degree of alignment.
U.S. Pat. No. Re. 31,601 to Ikeda et al discloses a fabric, useful as a substratum for artificial leather, which comprises a woven or knitted fabric constituent and a nonwoven fabric constituent. The nonwoven fabric constituent consists of numerous extremely fine individual fibers which have an average diameter of 0.1 to 6.0 microns and are randomly distributed and entangled with each other to form a body of nonwoven fabric. The nonwoven fabric constituent and the woven or knitted fabric constituent are superimposed and bonded together, to form a body of composite fabric, in such a manner that a portion of the extremely fine individual fibers and the nonwoven fabric constituent penetrate into the inside of the woven or knitted fabric constituent and are entangled with a portion of the fibers therein. The composite fabric is disclosed to be produced by superimposing the two fabric constituents on each other and jetting numerous fluid streams ejected under a pressure of from 15 to 100 kg/cm.sup.2 toward the surface of the fibrous web constituent. This patent discloses that the extremely fine fibers can be produced by using any of the conventional fiber-producing methods, preferably a meltblown method.
U.S. Pat. No. 4,190,695 to Niederhauser discloses lightweight composite fabrics suitable for general purpose wearing apparel, produced by a hydraulic needling process from short staple fibers and a substrate of continuous filaments formed into an ordered cross-directional array, the individual continuous filaments being interpenetrated by the short staple fibers and locked in place by the high frequency of staple fiber reversals. The formed composite fabrics can retain the staple fibers during laundering, and have comparable cover and fabric aesthetics to woven materials of higher basis weight.
U.S. Pat. No. 4,426,421 to Nakamae et al discloses a multi-layer composite sheet useful as a substrate for artificial leather, comprising at least three fibrous layers, namely, a superficial layer consisting of spun-laid extremely fine fibers entangled with each other, thereby forming a body of a nonwoven fibrous layer; an intermediate layer consisting of synthetic staple fibers entangled with each other to form a body of a nonwoven fibrous layer; and a base layer consisting of a woven or knitted fabric. The composite sheet is disclosed to be prepared by superimposing the layers together in the aforementioned order and, then, incorporating them together to form a body of composite sheet by means of a needle-punching or water-stream-ejecting under a high pressure. This patent discloses that the spun-laid extremely fine fibers can be produced by the meltblown method.
U.S. Pat. No. 4,442,161 to Kirayoglu et al discloses a spunlaced (hydraulically entangled) nonwoven fabric and a process for producing the fabric, wherein an assembly consisting essentially of wood pulp and synthetic organic fibers is treated, while on a supporting member, with fine columnar jets of water. This patent discloses it is preferred that the synthetic organic fibers be in the form of continuous filament nonwoven sheets and that the wood pulp fibers be in the form of paper sheets.
U.S. Pat. No. 4,476,186 to Kato et al discloses an entangled nonwoven fabric which includes a portion (a) comprised of fiber bundles of ultrafine fibers having a size not greater than about 0.5 denier, which bundles are entangled with one another, and a portion (b) comprised of ultrafine fibers to fine bundles of ultrafine fibers branching from the ultrafine bundles, which ultrafine bundles and fine bundles of ultrafine fibers are entangled with one another, and in which both portions (a) and (b) are non-uniformly distributed in the direction of fabric thickness.
U.S. Pat. No. 4,041,203 to Brock et al discloses a nonwoven fabric-like material comprising an integrated mat of generally discontinuous, thermoplastic polymeric micro-fibers and a web of substantially continuous and randomly deposited, molecularly oriented filaments of a thermoplastic polymer. The polymeric microfibers have an average fiber diameter of up to about 10 microns while the average diameter of filaments in the continuous filament web is in excess of about 12 microns. Attachment between the micro-fiber mat and continuous filament web is achieved at intermittent discrete regions in a manner so as to integrate the continuous filament web into an effective load-bearing constituent of the material. It is preferred that the discrete bond regions be formed by the application of heat and pressure at the intermittent areas. Other methods of ply attachment such as the use of independently applied adhesives or mechanically interlocking the fibers such as by needling techniques or the like can also be used. Other fabrics employing meltblown microfibers are disclosed in U.S. Pat. No. 3,916,447 to Thompson and U.S. Pat. No. 4,379,192 to Wahlquist et al.
U.S. Pat. No. 4,514,455 to Hwang discloses a composite nonwoven fabric which comprises a batt of crimped polyester staple fibers and a bonded sheet of substantially continuous polyester filaments. The batt and the sheet are in surface contact with each other and are attached to each other by a series of parallel seams having a spacing of at least 1.7 cm, and preferably no greater than 5 cm, between successive seams. In one embodiment of Hwang, the seams are jet tracks which are a result of hydraulic stitching.
However, it is desired to provide a nonwoven web material having improved hand and drape and in which the strength (wet and dry) of the web remains high. Moreover, it is desired to provide a cloth-like fabric which can have barrier properties and high strength. Furthermore, it is desired to provide a process for producing such material which allows for control of other product attributes, such as absorbency, wet strength, durability, low linting, etc.